CN106061616B - Long term storage of waste by adsorption with high surface area materials - Google Patents

Abstract

The present invention provides a system and method for long-term storage of waste that may include a comminuted material (100) having a high surface area. The pulverized material (100) may comprise processed hydrocarbon-containing material particles from which a hydrocarbon product has been obtained. The shredded material (100) may be contacted with flowable waste such that the flowable waste remains in the shredded material (100). This flowable waste is some material other than the hydrocarbon product obtained from the hydrocarbon-containing material. An encapsulation barrier (105) may encapsulate the shredded material (100) and provide an auxiliary means of preventing escape of the flowable waste material.

Description

Long-term waste storage using adsorption of high surface area materials

Related patent applications

This patent application claims US Provisional Patent Application No. 61/932,582, filed January 28, 2014, entitled "Long Term Storage of Waste Using Adsorption by High Surface Area Materials" of priority, this US Provisional Patent Application is incorporated herein by reference.

technical field

The present invention relates to systems and methods for long-term storage of flowable waste (eg, hazardous waste) in a body of high surface area material. Accordingly, the present invention relates generally to the technical fields of waste management, geology, materials science and fluid mechanics.

Background technique

As more and more unwanted waste is generated around the world, waste disposal is an increasingly challenging problem. Hazardous waste disposal in particular can involve complex and expensive measures to destroy or otherwise safely manage hazardous waste. If disposal methods are not adequately controlled, hazardous waste can escape into the surrounding environment and cause harm to plant and animal life, contamination of groundwater, and possibly other harm. Measures are often taken to immobilize hazardous waste to prevent it from escaping into the environment. Various methods have been developed, including encapsulating waste in hardened materials such as cement, resin, or glass, injecting waste into fissures in subterranean formations, and storing waste in trash that can be equipped with leak-proof linings and detection systems in landfill. However, various challenges remain in terms of stability, durability, reliability and economics of disposal sites.

SUMMARY OF THE INVENTION

Systems for long-term storage of waste may include comminuted materials with high surface areas. The pulverized material may include processed hydrocarbon-containing material particles from which the hydrocarbon product has been obtained. Flowable waste can be retained in the shredded material. This flowable waste material is a material other than the hydrocarbon product obtained from the hydrocarbon-containing material. The encapsulation barrier can encapsulate the comminuted material.

Additionally, the method for storing flowable waste can include contacting a substantially stationary body of shredded material with the flowable waste. The pulverized material can have a high surface area. The pulverized material may also include processed hydrocarbon-containing material particles from which the hydrocarbon product has been obtained. Finally, the comminuted material can be encapsulated by an encapsulation barrier.

Thus, a broad overview of the more important features of the invention has been presented in order to provide a better understanding of the detailed description of the invention that follows, and to better appreciate its contribution to the art. Other features of the present invention will become apparent from the following detailed description of the invention, taken in conjunction with the accompanying drawings and claims, or may be learned by practice of the invention.

Description of drawings

Figure 1 is a cross-section of a body of comminuted material wrapped by an encapsulation barrier in accordance with one embodiment of the present invention.

Figure 2 is a cross-section of a shredded material particle having flowable waste retained therein, according to one embodiment of the present invention.

3 is a flow diagram of a method for storing flowable waste according to one embodiment of the present invention.

It should be noted that the drawings are merely illustrative of several embodiments of the invention and are not intended to limit the scope of the invention thereby. Moreover, the drawings are generally not to scale, but are drawn for the purpose of convenience and clarity of illustration of various aspects of the present invention.

Detailed ways

While these exemplary embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, it should be understood that other embodiments may be practiced and various modifications may be made to the invention without departing from the spirit and scope of the invention. kind of change. Accordingly, the following more detailed description of embodiments of the present invention is not intended to limit the scope of the claimed invention, but is presented for purposes of illustration and not limitation only to describe the features and characteristics of the present invention, and to illustrate the present invention. the best mode of operation and is sufficient to enable those skilled in the art to practice the invention. Accordingly, the scope of the present invention is to be limited only by the appended claims.

definition

In describing and claiming the present invention, the following terminology will be used. The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a wall" includes reference to one or more of such structures, reference to "a waste" includes reference to one or more of such materials, and "a contacting step" refers to one or more multiple such steps.

As used herein, "shredding" refers to breaking up a construct or larger mass into smaller pieces, such as pieces typically less than about 2 feet in diameter. The pulverized agglomerates may be petrified or otherwise broken into pieces using any number of techniques, including crushing, detonation, and the like.

As used herein, "earth material" refers to natural materials recovered from soil by mechanical deformation only, such as, but not limited to, swelling clays (eg, bentonite, montmorillonite, kaolinite, illite, chlorite, vermiculite, etc.), gravel, rock, compacted fill, soil, etc. For example, gravel can be combined with cement to form concrete. Often, clay-modified soils can combine with water to form a hydrated layer that acts as a fluid barrier. In contrast, spent oil shale can be used in combination with the earth material used in the walls of the encapsulating barrier, but not the earth material as used herein because the pretreatment will embed the kerogen converted into hydrocarbon products.

As used herein, "flowable waste" refers to a material capable of flowing into a high surface area material under given conditions. Flowable waste can include liquids, gases, fine particles, vapors, or combinations thereof. As used herein, "hazardous material" or "hazardous waste" includes any material capable of causing harm to animals, people, or the environment and that exhibits one or more of the following characteristics: flammable, reactive, corrosive, toxic, or radioactivity. The Environmental Protection Agency defines many hazardous wastes in 40 C.F.R. 261 (July 1, 2012). However, any material that exhibits such properties to the extent that it is unsuitable for a given application or environment may be considered detrimental. For example, hazardous materials may also include radioactive materials, such as nuclear waste or related processing materials, which are Class A, B or C waste.

As used herein, "hydrocarbon-containing material" refers to a material comprising hydrocarbons from which hydrocarbon products can be extracted or derived. For example, liquid hydrocarbons can be extracted directly from the material, removed by solvent extraction, directly evaporated off, or otherwise liberated. However, many hydrocarbon-containing materials contain hydrocarbons, kerogen and/or bitumen, which are converted by heating and pyrolysis into higher quality hydrocarbon products, including oil and gas products. Hydrocarbon-containing materials may include, but are not limited to, oil shale, tar sands, coal, lignite, bitumen, peat, biomass, and other organic-rich rocks.

As used herein, "treated hydrocarbon-containing material" refers to a hydrocarbon-containing material from which a hydrocarbon product has been extracted or derived. For example, the liquid hydrocarbons can be extracted directly from the material, removed by solvent extraction, directly evaporated off, or otherwise removed. However, many hydrocarbon-containing materials contain kerogen or bitumen, which are converted to hydrocarbons by heating and pyrolysis. Hydrocarbon-containing materials may include, but are not limited to, oil shale, tar sands, coal, lignite, bitumen, peat, biomass, and other organic-rich rocks. This treated hydrocarbonaceous material may optionally be mixed with other materials such as rock, cement, resins, other raw earth materials, surfactants, binders, enzymes, biologically derived fillers, biological agents, inorganic agents, pre- body, salt and/or man-made materials.

As used herein, "mining" refers to the conditions under which material is moved or disturbed from an initial formation or geographic location to a different, second location. Typically, mined material can be produced by crushing, crushing, detonating, or otherwise removing material from the native formation for further use or disposal.

As used herein, "retention capacity" refers to the amount of flowable waste material within a body of comminuted material that can remain substantially stationary. Retention capacity can depend on many factors such as the surface area of the shredded material, the porosity of the shredded material, the void space in the shredded material, the amount of residual hydrocarbons or other materials left in the shredded material after processing, the flowable waste and the shredded material surface Intermolecular forces between, wettability of crushed material relative to flowable waste, capillary forces, viscosity of flowable waste, surface tension of flowable waste, density of flowable waste, temperature, and others that help reduce surface energy factor. The retention capacity is controlled, at least in part, by the reduction in surface energy of the flowable waste in contact with the body of comminuted material. Thus, the retention capacity can be a function of the properties of the body of shredded material and the flowable waste and the interaction between them, eg, the retention capacity of the body of shredded material can be different for different wastes. In general, retention capacity can be the maximum amount of flowable waste material that can be stably retained within the shredded material without waste flowing out of the shredded material or collecting at the bottom of the shredded material under the force of gravity.

As used herein, "substantially stationary" refers to a nearly stationary arrangement of the flowable waste within the comminuted material. This means that the flowable waste material has substantially no bulk flow, allowing small-scale flow (eg, flow within pores, flow within a wetting film layer surrounding the comminuted material, random convection, or flow between adjacent particles of the comminuted material). The substantially stationary flowable waste can also move if the comminuted material settles or settles in the encapsulation barrier. However, substantially stationary flowable waste does not undergo bulk flow, flow out of the bulk of the comminuted material, or collect at the bottom of the comminuted material under the force of gravity.

As used herein, "about" refers to the degree of deviation based on experimental error common to the particular property identified. The range provided by the term "about" will depend on the particular context and particular property and can be readily discerned by one of ordinary skill in the art. The term "about" is not intended to specify or limit equivalence, which may be assigned a particular value. Additionally, unless otherwise specified, the term "about" shall expressly include "exactly" consistent with the following discussion of ranges and numerical data.

As used herein, "adjacent" means that two structures or elements are in proximity. In particular, elements identified as "adjacent" may be contiguous or connected. Such elements may also be close or proximate to each other without necessarily touching each other. In some cases, the exact proximity may depend on the situation.

Concentrations, dimensions, amounts, and other numerical data may be presented herein in range format. It should be understood that such range formats are used only for convenience and brevity, and are to be flexibly read to include not only the values explicitly recited as range endpoints, but also all individual values or subranges subsumed within the range, as if expressly Record each value and subrange. For example, a range of about 1 to about 200 should be read to include not only the explicitly recited endpoints of 1 and about 200, but also individual dimensions such as 2, 3, 4, and subranges such as 10 to 50, 20 to 100, and the like.

As used herein, for convenience, multiple items, structural elements, constituent elements and/or materials may be represented in the same list. However, these lists should be understood to mean that each member of the list is independently identified as a separate and unique member. Accordingly, no single member of such a list should be construed as the actual equivalent of any other member of the same list solely based on their occurrence in the same group, without an indication to the contrary.

Any steps recited in any method or process claims may be performed in any order and are not limited to the order presented in the claims. A means-plus-function or step-plus-function limitation will only be used where, for a particular claim limitation, all of the following conditions are met in that limitation: a) it expressly recites "means for" or "with and b) the corresponding function is then explicitly described. The structures, materials, or behaviors that support means-plus-function are expressly recited in the descriptions herein. Accordingly, the scope of the invention should be determined only by the appended claims and their legal equivalents, rather than by the description and examples given herein.

long-term storage of waste

Systems for long-term storage of waste generally work by retaining flowable waste within a stationary body of shredded material. The pulverized material can have a high surface area and can comprise processed hydrocarbon-containing material particles from which the hydrocarbon product has been obtained. Waste can be any flowable hazardous or non-hazardous material that is desired to be disposed of by long-term storage. The shredded material can have a retention capacity, which is the amount of flowable waste material that can remain substantially stationary within the shredded material. The retention capacity may depend on a variety of factors, such as the surface area of the comminuted material, the porosity of the comminuted material, the intermolecular forces between the surface of the flowable waste and the comminuted material, the viscosity of the flowable waste, the surface tension of the flowable waste, and the like. In general, the retention capacity may be the maximum amount of flowable waste material that can be stably retained within the shredded material without waste flowing out of the shredded material or collecting at the bottom of the shredded material under the force of gravity. Additionally, the encapsulation barrier can encapsulate the comminuted material. Encapsulation barriers can be used as an auxiliary measure to prevent waste from escaping. In some embodiments, the encapsulation barrier may be completely impermeable to waste. In other cases, the encapsulation barrier may be partially impermeable to the waste material. In general, a partially impermeable barrier can reduce waste diffusion to less than 10%, in some cases less than 5%, and in other cases less than 1% of the diffusion without the barrier.

In view of the above, a system for long-term storage of waste may include a body of comminuted material surrounded by an encapsulating barrier. Referring to FIG. 1 , the system includes a comminuted material 100 surrounded by an encapsulation barrier 105 . The crushed material may be fragments of larger clumps that have been petrified or otherwise broken up, such as petrified rock formations. Particles of comminuted material can have a variety of sizes and shapes. As shown in FIG. 2, particles 200 of comminuted material may be irregularly shaped. Each particle has the longest dimension 205 . The size of the particles can vary, but in some embodiments, the longest dimension of the majority of the particles by volume can be between about one millimeter (1 mm) and about thirty centimeters (30 cm). The size and shape of the particles can depend on the design of the system and the method used to crush the pulverized material. In some embodiments, the particles may have a broad distribution of longest dimensions, eg, the longest dimensions are randomly distributed between about one millimeter and about thirty centimeters. In other embodiments, the longest dimension may be more uniform. The surface area of the pulverized material can be affected by the size and shape of the particles. For example, smaller particles may have a larger surface area than larger particles of equal volume. As a general guideline, more than 90% of the particles may have a low aspect ratio of less than 5:1, and in most cases less than 2:1. In addition, although not required, the particles may have a non-uniform shape that varies from particle to particle.

The comminuted material 100 can have a high surface area, and generally can be very large in volume, such that the system can retain a substantial volume of waste. For example, typical storage systems may be formed with volumes in excess of about 1000 m ³ to 1.6 million m ³ . The size of the system can range from about 10m to 200m in depth and 0.5 acres to 5 acres in plan surface area.

The pulverized material can have a high surface area. The surface area of the comminuted material may contribute to the retention capacity of the comminuted material. For example, high surface area can result in greater magnitudes of surface tension and capillary forces between the comminuted material and the waste. The waste material may adhere to the surface of the shredded material particles, thereby being retained in the bulk of the shredded material. As shown in FIG. 2, the flowable waste material 210 may adhere to the particles 200 of the shredded material. The flowable waste can form a film 215 on the surface 220 of the particles and also collect in the voids between the particles. The thickness of the membrane and thus the amount of waste that can be retained depends on factors such as the surface tension, viscosity and density of the waste, as well as the shape, surface area and wettability of the comminuted material with respect to the waste. In some cases, the film may be a wet film, or in other words, a stable film obtained by wetting the surface of the comminuted material with waste material. Waste can also be retained in the interstitial spaces 225 between the particles.

The pulverized material may also typically be a porous material. Pores increase the surface area of the comminuted material and also increase retention capacity by absorbing waste material into the pores. As shown in FIG. 2 , particles 200 of pulverized material may have pores 230 with exposed openings at particle surfaces 220 . In some cases, the hole may have an interior volume that is completely filled with waste 210 . Thus, waste material can be absorbed into the particles of the comminuted material. In other cases, the inner surface 235 of the hole may be wetted by the membrane 215 of waste without the waste filling the inner volume of the hole.

Both high surface area and high porosity can be beneficial for the retention capacity of the pulverized material. Retention capacity can be affected by a number of factors, including void space in the shredded material, capillary forces, intermolecular forces, wettability of the shredded material relative to the scrap, surface area of the shredded material, porosity of the shredded material, temperature, Viscosity, density of waste, etc. The greater the retention capacity, the more waste can be stored in the shredded material. In some embodiments, the shredded material may retain an amount of waste material equal to the retention capacity. In other embodiments, the shredded material may contain scrap in an amount below the retention capacity, such as within 20% of the retention capacity, in some cases within 10% of the retention capacity, and in other cases within 5% of the retention capacity . Storing an amount of scrap less than the retention capacity provides a safety margin to ensure that scrap does not escape from the shredded material. Because systems for long-term storage of waste can be designed to retain waste for a long period of time, using a safety margin can help prevent the possibility of waste being lost due to abnormal conditions or events. Although the storage time may be determined by the specific application, the designed storage time may be at least 5 years, in some cases at least 20 years, and in other cases at least 100 years.

While shredded material can typically retain amounts of waste material up to the retention capacity, it is conceivable that waste material can escape if conditions change sufficiently, such as large temperature changes, weather changes (such as floods or heavy rain) or Displacement of soil under or around the shredded material or changes in the properties of the waste. In these cases, storing an amount less than the retention capacity can reduce the risk of escape of waste material. In some embodiments, the waste material is present in an amount less than about 90% of the retention capacity of the shredded material. In other embodiments, the waste material is present in an amount less than about 70% of the retention capacity of the shredded material, providing a wider safety margin. However, when swelling clays are used as the barrier material, changes in groundwater or hydration levels generally do not compromise the barrier properties of the system.

The pulverized material may include processed hydrocarbon-containing material particles from which the hydrocarbon product has been obtained. Spent hydrocarbon-containing materials can often have very high surface areas. For example, oil shale is a hydrocarbon-rich rock that can become highly porous after the hydrocarbons are removed. Untreated oil shale contains kerogen, organic material bound to an inorganic matrix rich in mineral material. Kerogen can be found in thin layers and pockets throughout the oil shale. After removal of the kerogen by pyrolysis, an inorganic matrix with a network of pores previously at least partially occupied by the kerogen is left behind. In addition, mechanical weak points formed in oil shale during pyrolysis can form a network of fractures and voids, which further increase the porosity of spent oil shale. In some embodiments, the hydrocarbonaceous material treated in the pulverized material may be spent oil shale, spent tar sands, coal residues, lignite residues, bitumen residues, or mixtures thereof. The treated hydrocarbonaceous material may be an undesired residual product of a hydrocarbon extraction operation. Thus, the use of treated hydrocarbonaceous material in a system for long-term storage of waste may provide a convenient way to dispose of flowable waste and undesired treated hydrocarbonaceous material simultaneously.

In some embodiments, the pulverized material may contain substantially only the processed hydrocarbon-containing material from which the hydrocarbon product has been obtained. However, in other embodiments, the comminuted material may comprise other optional materials. Low quality oil shale may be included in the crushed material, for example, if the oil shale does not contain a sufficient amount of kerogen to make extraction profitable. In some embodiments, the comminuted material may comprise other raw earth materials, such as clay, compacted fill, refractory cement, cement, expansive clay-modified soil, compacted soil, low-quality shale, and combinations thereof. However, the untreated hydrocarbon-containing material may most often comprise less than 50% by volume, and in some cases less than 10% by volume, of the storage body comprising the treated of hydrocarbon-containing materials.

As previously discussed, the flowable waste can be retained in the shredded material. As a flowable material, the waste can be pumped or poured into the body of shredded material. In some embodiments, the waste material may be a liquid. Liquid waste may be substantially only liquid, or may contain solid particles to form a slurry or suspension. Furthermore, the liquid waste can contain any type of liquid material. For example, liquid waste may contain substantially pure liquid chemicals, mixtures of chemicals, and dissolved solids and gases. In another optional aspect, the flowable waste material may be gas or flowable particles. An example of flowable waste particles may be calcined waste, or particulate fines produced as a by-product of a primary waste treatment process.

The flowable waste can flow into the shredded material, allowing the flowable scrap to form a wet film, fill interstitial spaces, and be absorbed into pores in the shredded material or otherwise adsorbed on the surface of the shredded material. In some embodiments, the waste material may form a wetting film around the shredded material. The wetting film is a stable film obtained by wetting the surface of the shredded material by the scrap and can have different thicknesses depending on the adhesion between the scrap and the shredded material and other factors such as the surface tension of the scrap. As shown in FIG. 2, the film 215 of the waste material 210 may be substantially adapted to the surface 220 of the particles 200 of the shredded material. The film thickness can be different at different locations, depending on the geometry of the particles and the proximity of other particles. Additionally, the film surrounding two adjacent particles can merge together and form a continuous area of waste retained between the particles. In some embodiments, the waste material may form a wetting film around at least a majority of the comminuted material by volume. Even a thin wetting film can hold large volumes of waste if a wetting film is formed around most high surface area comminuted materials. In some cases, the waste material may fill the interstitial spaces 225 between the particles, while in other cases, the interstitial spaces may contain membranes of waste material and empty void spaces. Additionally, waste material can flow into and fill the holes 230, thereby being absorbed into the particles of the comminuted material.

The waste material may remain within the shredded material such that the waste material is substantially stationary. If the waste is present in an amount equal to or less than the retention capacity of the comminuted material, the waste can be substantially stationary since it will be in the form of a wetting film, trapped in interstitial spaces, or adsorbed in the pores of the comminuted material. Thus, the waste material may be present in an amount such that the waste material does not flow out of the body of shredded material or collect at the bottom of the body of shredded material under the force of gravity. When the comminuted and barrier materials are raw earth materials or other natural materials, the stability and retention of the retained waste can be extended indefinitely. Thus, the retention systems described herein can effectively retain flowable waste as long as catastrophic failure of the barrier is avoided.

Hazardous waste can be efficiently disposed of by being stored in the system according to the invention. Disposal of hazardous waste can be challenging due to its potential harm to people and the environment. The system of the present invention can retain hazardous waste for an extended period of time and, in most cases, indefinitely ensure that the hazardous waste does not escape into the environment. Hazardous waste may generally include hazardous materials having one or more of the following properties in excess of moderate ranges: high flammability, high reactivity, corrosiveness, toxicity, and radioactivity. The temperature of the system can also affect the stability or hazard level of some hazardous wastes. Detailed definitions of these properties and a list of specific hazardous wastes have been published by the Environmental Protection Agency. Hazardous waste suitable for storage using the present invention may include flowable hazardous waste identified in 40 C.F.R. 261 (July 1, 2012), although other hazardous materials may also be stored. Other materials, such as radioactive materials, can also be hazardous waste. In some embodiments of the invention, the flowable waste may be a hazardous material selected from the group consisting of radioactive waste, chemical waste, pesticides, automotive waste, solvents, corrosives, heavy metal-containing waste, refrigerants, biological waste, biohazards Sexual materials, immobilized biological materials, and mixtures thereof. Specific non-limiting examples of hazardous materials may include mercury, arsenic, cadmium, and the like.

The flowable waste can generally be anything other than residual hydrocarbon products or other process residues or the like that remain after the hydrocarbons have been derived from the hydrocarbonaceous material. While the goal of the hydrocarbon production process is to remove as much hydrocarbons as possible from the hydrocarbonaceous material, a certain amount of residual hydrocarbons may remain in the treated spent hydrocarbonaceous material. The residual amount of residual hydrocarbons can vary depending on various factors. For example, poor temperature control in the hydrocarbon production stage can result in less efficient hydrocarbon production, thereby leaving more residual hydrocarbons. Even though these residual hydrocarbons are flowable in some cases and can be considered waste since they are not recovered as useful products, in the present invention they refer to residual recovery process materials and non-flowable wastes . Herein, the term flowable waste refers to waste added to the comminuted material regardless of the nature of the residual recycling process material present in the comminuted material prior to the introduction of the flowable waste.

Metals and other chemicals in oil shale can be examples of residual recovery process materials left in processed hydrocarbon-containing materials during hydrocarbon recovery. Some of these residual recycling process materials can be considered hazardous. The flowable waste of the present invention may be some other material than these leftover metals and chemicals. Typically, the flowable waste material stored in the comminuted material may be a foreign material (ie, not a produced component) that was not originally present in the hydrocarbon-containing material. For example, flowable waste can be transported from a remote location for storage in shredded material. Flowable waste can also be generated from on-site processing outside the bulk of the shredded material, such as on-site at a hydrocarbon refinery. Accordingly, materials such as hydrocarbon products produced, carbon dioxide produced, or other products (including by-products) of the recycling process are not considered flowable waste. In an alternative, pulverized material can be used to capture or store residues from the extraction process. Non-limiting examples of extraction processes may include cyanide leaching in gold or copper extraction operations, extraction of uranium from spent shale, and the like. During these processes, the pulverized material can act as an extraction space for the extraction process. Alternatively, the comminuted material may simply serve as a storage space to place residues from the spatially separated extraction process after extraction.

Residual recovery process materials, such as hydrocarbons, metals and other chemicals left in the treated hydrocarbonaceous material, can affect the retention capacity of the comminuted material. The pulverized material may have less exposed surface area due to, for example, the presence of adsorbed residual hydrocarbons. In some cases, residual hydrocarbons can plug pores and further reduce retention capacity. Conversely, such residual hydrocarbons, carbon, and other species can increase the favorable surface energy for capturing flowable waste and, therefore, can reduce the combined surface energy sufficient to improve adhesion and retention capacity within the comminuted material. The above factors can be considered when determining the retention capacity of the shredded material to avoid overfilling the shredded material with flowable waste.

The shredded material can be wrapped by an optional encapsulation barrier to provide a secondary barrier to the waste material exiting the system. The encapsulation barrier may include a bottom portion, a top portion, and a sidewall portion connecting the bottom and the top to form an enclosed volume that contains the comminuted material and restricts fluid flow out of the encapsulation barrier. In some embodiments, the encapsulation barrier may have one or more fluid inlets and outlets. These fluid inlets and outlets can be used in the production of hydrocarbon products from hydrocarbonaceous material within the encapsulation barrier, and can also be used to introduce flowable waste into the comminuted material inside the encapsulation barrier. The top portion defines an upper portion of the enclosed volume and abuts the side walls. The bottom also adjoins the side walls and can be substantially horizontal or sloped toward the discharge conduit as desired for collecting hydrocarbon fluids extracted during processing of the hydrocarbon-containing material. Before the flowable waste is introduced, the collection discharge line can be blocked or plugged to prevent waste from escaping.

In some embodiments, encapsulating barriers may be formed along the walls of the excavated hydrocarbonaceous material deposit. For example, oil shale, tar sands, or coal can be mined from a deposit to form a cavity roughly corresponding to the encapsulation volume required to encapsulate the barrier. The excavated cavity can then be used as a support for the encapsulation barrier. In an alternative embodiment, if the encapsulation barrier is located partially or substantially above the ground, a guard may be formed around the outer wall surface of the encapsulation barrier. The encapsulation barrier may be part of a free-standing structure on the ground, wherein the platform supports the side walls and the bottom of the barrier is supported by the ground below it.

The encapsulation barrier may be substantially free of undisturbed formations. Specifically, the encapsulation barrier can be fully constructed and artificially created as a separate isolation mechanism for preventing uncontrolled migration of waste material out of the shredded material. An undisturbed formation may have fractures and pores that allow flowable waste to permeate through the formation. Forming the encapsulation barrier as a fully man-made structure, without using the undisturbed formation as a bottom or wall, reduces the risk of waste seepage through the formation. However, in some embodiments, the encapsulation barrier may employ some component of the surface of the excavated formation. For example, in some formations, the bottoms and walls of excavated tunnels may have sufficiently low natural permeability that a significant barrier (eg, clay-amended soil) may not be necessary for the barrier portion.

The encapsulation barrier may generally include a bottom, sidewalls and a top to define an enclosed volume, with the sidewalls extending upwardly from the bottom and the top extending over the sidewalls. Each of the bottom, side walls, and top may be composed of multiple layers including an inner layer of fines or other barrier material, and an outer layer of swelling clay modified soil or similar fluid barrier material. Optionally, in addition to expanding clay-modified soil, an outer membrane that further prevents fluid flow beyond the encapsulated barrier may be employed as a fluid barrier. The outer membrane can be used as a secondary backup seal in the event that the primary seal fails for any reason. An inner layer of high temperature bitumen or other fluid barrier material may also optionally be applied to the inner surface of the fines layer and define the inner surface of the encapsulating barrier.

Swelling clays are hydratable inorganic materials that cause the clay to swell, or otherwise form a barrier to fluid flow. The encapsulated barrier can be formed from dry clay particles and other raw earth materials, which can then be hydrated to swell the clay particles and form the barrier. Typically, such a barrier layer may be formed from solid phase particles and liquid phase water, which together form a substantially continuous fluid barrier. For example, swelling clay-modified soils can be used to form the bottom, walls, and top of the encapsulating barrier. When swelling clay is hydrated, it expands and fills the void spaces between particles of other materials in the soil. In this way, the swelling clay-modified soil becomes less permeable to flowable waste inside the encapsulation barrier. The encapsulating barrier can be substantially impermeable to fluid flow by intimately mixing the swelling clay with other raw earth materials. Some examples of suitable swelling clays include bentonite, montmorillonite, kaolinite, illite, chlorite, vermiculite, slate, smectite, and the like.

The combined multiple layers form an encapsulating barrier that acts as a barrier to the crushed material, thereby maintaining heat within the enclosed volume to facilitate the extraction of hydrocarbons from oil shale, tar sands, or other hydrocarbon-bearing materials. The plasticity of the expansive clay-modified soil layer seals the barrier, preventing waste from leaking out of the barrier. The insulating properties of the fine-grained layer allow a temperature gradient across the layer to allow the expansive clay-modified soil layer to cool enough to retain moisture. This property prevents migration of hydrocarbons out of the barrier (other than via designated conduits) during the generation of hydrocarbons from hydrocarbon-containing materials. This property also prevents the waste from escaping out of the barrier after the flowable waste is stored in the shredded material. However, consistent with the description herein, it may be desirable to fill the comminuted material with flowable waste at volumes below the retention capacity. In this way, within each zone, the pooling or local concentration of waste beyond the retention capacity of the material can be avoided, thereby limiting or completely eliminating the reliance on such external auxiliary barriers.

In some cases, the insulating fine particle layer can be omitted from the encapsulation barrier. For example, an insulating layer is optional if the comminuted material is subjected to an alternative process (eg, solvent extraction or leaching) that does not require the application or generation of heat in order to remove substances therefrom. In such an embodiment, the soil layer modified with the hydrated swelling clay seals the enclosed volume containing the comminuted material from the external environment. A suitable impermeable membrane may optionally be lined with the inner surface of the hydrated swelling clay modified soil layer. Although not always desirable, this lining prevents interaction between the hydrated swelling clay-modified soil layer and the solvent and/or leached fluid that might otherwise Reacts with or damages hydrated swelling clay-modified soils.

In use, the insulating layer can often be formed from a fine particle layer. Typically, the fine-grained layer may be particulate material less than 3 cm in diameter. Although other materials may be suitable, the fine-grained layer is typically made of gravel, sand, crushed oil-lean shale, or other particulate fines that do not trap or otherwise inhibit fluid flow. By choosing the right particulate material and layer thickness, the fine-grained layer can act as the main source of insulation and can maintain a considerable thermal gradient from the inner surface to the outer surface. Gases can penetrate the permeable fine-grained layer, but are substantially impermeable to the encapsulated swelling clay layer. As in the case of the hydrocarbon extraction process, when the temperature of the pulverized material is higher than the temperature of the inner surface of the encapsulated expanding clay layer, the gas can be sufficiently cooled in the fine-grained layer (below the condensation point of the corresponding gas), and the liquid can be removed from the Condensed out of the gas. These liquids then drip through the granules to the bottom of the encapsulation barrier, where they pool and are removed.

The encapsulation barrier may be formed using any suitable method. However, in one aspect, the barrier is formed from bottom to top. In a vertical deposition process in which material is deposited in a predetermined pattern, the process of forming the one or more walls and the process of filling the package with pulverized material may be performed simultaneously. For example, multiple chutes or other particle delivery mechanisms may be oriented along respective locations above the deposition material. By selectively controlling the volume of particles delivered, and where along the bird's eye view of the system each individual granular material is delivered, layers and structures can be formed simultaneously from bottom to top. The sidewall portion of the barrier can be formed as a continuous upward projection at the outer perimeter of the bottom, and each layer present, including the expansive clay modified soil layer, the fine-grained layer, and the membrane and/or bituminous lining Layers, if present, are constructed as continuous extensions of the bottom counterparts. During the construction of the side wall, the comminuted material can be placed both on the bottom and within the perimeter of the side wall, so that the filling of the volume that will become the enclosed space occurs concurrently with the continuous building up of the side wall. In this way, the formation of internal retaining walls or other lateral constraints can be avoided. This method can also be monitored during vertical stacking in order to verify that the mixing that occurs at the interfaces of the layers is within acceptable predetermined tolerances (eg, to maintain the functionality of the layers). For example, excessive blending of an expansive clay-modified soil layer with fines may impair the sealing function of the expansive clay-modified soil layer. This over-mixing phenomenon can be avoided by carefully depositing each adjacent layer during construction, and/or by increasing the thickness of the deposited layers.

As the build process approaches the upper portion, the top can be formed using the same conveyor mechanism as described above, and only the location and speed of deposition of the appropriate material to form the top layer need to be adjusted. For example, when the desired height of the sidewalls is reached, a sufficient amount of encapsulation barrier material can be added to form the top.

Regardless of the specific method employed to form the encapsulating barrier, the bottom is generally formed first, and the method may include placing an optional outer membrane, expansive clay modified soil layer, and fines layer. Optionally, a bitumen layer may be disposed adjacent to the inner surface of the fines layer. Depending on the specific installation, heating tubes, collection tubes, fluid delivery tubes, collection trays, and/or other structures can optionally be embedded into the deposited comminuted material. The formed barrier may also have a cover layer disposed on top. If a barrier is to be formed below an existing slope, the cavernous pit can be prepared by an excavation step or other suitable steps. If the barrier is not located in a subterranean location, soil or other support pads may surround the sidewalls and support the layer material as the layer material is deposited.

In view of the above description, FIG. 1 shows a side view of one embodiment of an encapsulation barrier 105 surrounding a shredded material 100 . The existing surface or excavation slope 110 is used primarily as support for the bottom portion 115 of the barrier. The bottom portion includes an optional outer membrane 118 , a swelling clay modified soil layer 120 , an insulating fines layer 122 , and optionally an inner asphalt layer 124 . The continuous sidewall section 130 is constructed from the bottom section upwards and includes an outer membrane 132 , a layer of expansive clay modified soil 134 , a layer of fines 136 and optionally an inner layer of asphalt 138 . As mentioned earlier, as the barrier is constructed, the layers can be formed simultaneously from the bottom to the top. Additionally, as the walls are built, pulverized material (eg, oil shale, tar sands, coal, etc.) can be placed on the bottom and fill the enclosed volume that will be formed. Depending on the placement of the system, the outer surfaces of the sidewall and bottom portions may be supported by the guard or (if excavated) by the bottom and walls of the excavation tunnel. Each of the bottom portion, walls, and top portion 140 of the barrier together form an insulating containment layer. Generally, these portions of the layers are continuous layers surrounding the comminuted material.

Once the sidewall portions 130 are constructed, either simultaneously or individually, the comminuted material 100 is placed within the enclosed volume to be formed. The top portion 140 may be formed over the shredded material and adjoin the sidewall portion. As with the bottom and sidewalls, the top may have multiple layers, including an optional outer membrane 142 , an expanded clay modified soil layer 144 , a fines layer 146 and optionally an inner asphalt layer 148 . Cover layer 150 may also cover the top, if desired. Additionally, the material used as the cover layer can be used as the sidewall or bottom to wrap or surround the barrier.

The bottom, sidewall and top layers are continuous and are in direct contact or communication with similar materials such that, for example, the fine particle layers 122, 136 and 146 are one continuous layer surrounding the enclosed volume. The same applies to outer membrane layers 118, 132, and 142, expanding clay modified soil layers 120, 134, and 144, as well as inner asphalt layers 124, 138, and 148 (if used). Notably, the thickness of each layer may not be uniform throughout the barrier. The thickness of each layer is not critical, as long as the thickness of the layer is functional for its intended purpose (eg, insulation, fluid barrier, etc.), the presence of the layer is what matters. Although the thickness of the encapsulation barrier can vary, a suitable thickness can generally range from about 4 cm to about 2 m.

A method of storing flowable waste may include contacting a substantially stationary body of comminuted material with the flowable waste. The comminuted material can have a high surface area to allow the comminuted material to have a high retention capacity. The pulverized material may include processed hydrocarbon-containing material particles from which the hydrocarbon product has been obtained. The encapsulation barrier can encapsulate the comminuted material.

The types of materials used in the method and their properties and characteristics may be the same as described above for the system for storing flowable waste. The pulverized material may be of the same particle size, surface area and material as described above. Similarly, the flowable waste used in the method can include all flowable wastes described above, including hazardous and non-hazardous wastes. The encapsulation barrier can also have the same materials, construction, and construction methods described above.

In some embodiments, the step of contacting the substantially stationary body of shredded material with the flowable waste material may include injecting the flowable waste material into the shredded material. The injection operation can be carried out by pumping waste material from the outside of the encapsulation barrier to the inside of the encapsulation barrier through tubing. In some cases, the piping may be the same piping used in the hydrocarbon production stage for injecting heating fluids or removing hydrocarbon products. In other embodiments, the step of contacting the shredded material with the waste material may be performed in other ways. The waste material can be mixed with the shredded material prior to its introduction into the encapsulation barrier. In any event, the introduction of flowable waste can be performed to minimize local pooling or retention of waste that exceeds the volume void. Thus, the flowable waste can be distributed throughout the shredded material to increase uniformity and utilize the storage capacity of the entire body of shredded material. This can be accomplished using multiple distribution inlets, existing embedded piping, and/or monitoring flowable waste at various locations. Often, the introduction of waste material into the shredded material can locally provide a large amount of waste material that exceeds the retention capacity. Therefore, once the local retention capacity is reached, excess flowable waste will flow into the shredded material in the nearby lower region. Monitoring the waste level and/or modeling the total volume capacity can be used to determine the volume of flowable waste that can be introduced into a given volume of comminuted material while not exceeding the retention capacity of the total volume.

The method may also include performing a hydrocarbon production stage to remove hydrocarbons from the comminuted material prior to the step of contacting the comminuted material with the flowable waste material. FIG. 3 illustrates an exemplary method 300 that includes extracting 310 hydrocarbons from hydrocarbon-containing material within an encapsulation barrier and contacting a substantially stationary body of comminuted material with flowable waste. As mentioned above, the pulverized material has a high surface area and contains processed hydrocarbon-containing material particles from which the hydrocarbon product has been obtained. The shredded material is also wrapped 320 by an encapsulation barrier.

The foregoing detailed description describes the invention with reference to specific exemplary embodiments. However, it should be understood that various modifications and changes may be made without departing from the scope of the present invention as set forth in the appended claims. The detailed description and drawings are to be regarded as illustrative only and not restrictive, and all such modifications or alterations, if any, are intended to fall within the scope of the invention as described and illustrated herein Inside.

Claims (34)

1. A system for long term storage of waste comprising:

a) a comminuted material having an average longest particle size of from about 1mm to about 30cm and a high surface area and a flowable liquid waste material that remains stationary within the interstitial spaces and in pores of the comminuted material for at least 5 years, the comminuted material comprising particles of treated hydrocarbonaceous material from which a product has been derived; and

b) an encapsulation barrier surrounding the comminuted material;

wherein the waste is not the product.

2. The system of claim 1, wherein the processed hydrocarbonaceous material is selected from spent oil shale, spent tar sands, coal residue, bitumen residue, or mixtures thereof.

3. The system of claim 2, wherein the coal residue is lignite residue.

4. The system of claim 1, wherein the encapsulation barrier comprises a raw earth material selected from the group consisting of: clay, cement, clay-modified soil, compacted soil, low-grade shale, or combinations thereof.

5. The system of claim 4, wherein the clay is a swelling clay.

6. The system of claim 5, wherein the swelling clay is selected from montmorillonite, kaolinite, illite, chlorite, or vermiculite.

7. The system of claim 4, wherein the clay-modified soil is bentonite.

8. The system of claim 4, wherein the compacted earth is compacted fill.

9. The system of claim 4, wherein the cement is a refractory cement.

10. The system of claim 1, wherein the encapsulation barrier is a free-standing or undisturbed formation.

11. The system of claim 1, wherein the flowable waste material comprises a material selected from the group consisting of: radioactive waste, pesticides, automotive waste, solvents, caustic, refrigerants, biological waste, extraction residues, and mixtures thereof.

12. The system of claim 11, wherein the biowaste is biohazardous waste.

13. The system of claim 1, wherein the flowable waste material comprises heavy metal-containing waste.

14. The system of claim 1, wherein the flowable waste material comprises chemical waste.

15. The system of claim 1, wherein the waste material forms a wetting film around the comminuted material.

16. The system of claim 1, wherein the waste material is present in an amount equal to or less than a retention capacity of the comminuted material.

17. The system of claim 1, wherein the comminuted material further comprises a raw soil material selected from the group consisting of: clay, cement, expansive clay modified soil, compacted soil, low grade shale, or combinations thereof.

18. The system of claim 17, wherein the compacted earth is compacted fill.

19. The system of claim 17, wherein the cement is a refractory cement.

20. A method for storing flowable waste comprising contacting a substantially stationary body of comminuted material with flowable liquid waste, the comminuted material having an average longest particle size of from about 1mm to about 30cm and a high surface area, the comminuted material comprising treated particles of hydrocarbonaceous material from which hydrocarbon products have been derived, the comminuted material being surrounded by an encapsulation barrier and the flowable liquid waste being stored within pores of the comminuted material and interstitial spaces within the comminuted material, and allowing the flowable liquid waste to remain stationary in the pores and interstitial spaces for at least 5 years.

21. The method of claim 20, wherein the treated hydrocarbonaceous material is selected from spent oil shale, spent tar sands, coal residue, bitumen residue, or mixtures thereof.

22. The method of claim 21, wherein the coal residue is lignite residue.

23. The method of claim 20, wherein the encapsulation barrier comprises a raw earth material selected from the group consisting of: clay, cement, clay-modified soil, compacted soil, low-grade shale, or combinations thereof.

24. The method of claim 23, wherein the clay is a swelling clay.

25. The method of claim 24, wherein the swelling clay is selected from montmorillonite, kaolinite, illite, chlorite, or vermiculite.

26. The method of claim 23, wherein the clay-modified clay is bentonite.

27. The method of claim 23, wherein the compacted earth is compacted fill.

28. The method of claim 23, wherein the cement is a refractory cement.

29. The method of claim 20, wherein the waste material is a hazardous material.

30. The method of claim 20, wherein the waste material forms a wetting film around the comminuted material.

31. The method of claim 20, wherein the waste material is present in an amount equal to or less than a retention capacity of the comminuted material.

32. The method of claim 20, wherein contacting comprises injecting the waste material into the comminuted material.

33. The method of claim 20, further comprising extracting hydrocarbon products from hydrocarbonaceous materials within the encapsulation barrier prior to contacting the comminuted material with the waste material, wherein a retention capacity of the hydrocarbonaceous materials is increased during the extracting.

34. The method of claim 20, wherein the comminuted material is contacted with the flowable waste material after the comminuted material has been wrapped by the encapsulation barrier.

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